Heat exchangers of the type which are typically employed in air conditioning systems for example for automobiles comprise opposed manifolds provided with a large number of heat exchange tubes which carry coolant fluid between the manifolds. Each manifold comprises a tubular body which is internally divided by partitions or walls into a plurality of compartments to define a tortuous path for the coolant fluid through the heat exchange tubes. Such manifolds may be formed of two channel-like half shells which are joined together along their longitudinal edges to form the manifold, with the partitions located transversely within the manifold.
With such an assembly, particular difficulties arise in accurately locating the partitions or wall members within the manifold. If these are not accurately located problems of leaking of the manifold can arise, as well as problems of partial obstructions of the heat exchange openings. It is known to seat these partitions in circumferential grooves machined on the internal surfaces of the tank and header part which serve to position the partitions longitudinally therein. The problem with this arrangement is that in forming the grooves the wall of the tank material is liable to deform, and in particular to elongate so that the intended groove locations cannot be accurately maintained. It is also known to provide the tank part with seating slots extending entirely through the wall thickness into which the partitions are laterally fitted from outside of the manifold. It is similarly difficult to accurately locate the slots at the desired positions. Moreover, the slots provide additional possible leakage paths for coolant fluid.
In U.S. Pat. No. 5,233,756 there is disclosed a tubular manifold in which the partitions are held in position by deforming the tubular manifold wall on either side of the partitions by applying a circumferential beading. The tubular wall here is also deformed about the apertures in the wall provided for the heat exchange tubes, which deformation further serves to retain the partitions in position. This concept is disclosed in relation to a manifold which is of the type which has a tubular unitary construction whereby the partitions must be introduced into the manifold from an end of the tube prior to the deformation.